fixes #26104; prevent compile-time-only typeof from being treated a… (#26105)

…s a runtime alias

fixes #26104

Follows up https://github.com/nim-lang/Nim/pull/25994

tests/ccgbugs/t26104.nim

@@ -0,0 +1,16 @@
+discard """
+  action: compile
+  ccodeCheck: "@'((*Result).f);' .*"
+"""
+
+# bug #26104: a compile-time-only `typeof` argument was treated as a runtime
+# alias of the result field, forcing an unnecessarily large temporary and copy.
+type
+  B = array[131072, byte]
+  Y = object
+    f: B
+
+proc fill(_: type B): B = discard
+proc make(): Y = result.f = fill(typeof(result.f))
+
+discard make()